ingnition problems

Went to fire up the dog and no power to the starter! battery was good but the ingnition switch fobared.Now my ? is ive got a 1000amp battery a 100amp alternator and its wired like a 1976 dodge dart. eccept ive rewired the dash wth new auto meter gages fused when needed. now my volt meter on the dash shows 14.7 volts when running/12.8 with ingnition in on postion.but this is what is weird my tach dose this little dance when starting it does a 360 and when running at idol it bonces around from 800 to 1100 Now im still working out the gremlins with the lites.NUTZART!